Koh Lanta's weather follows a unique pattern and should be taken into consideration for the timing of your visit to one of Thailand's most beautiful islands.
Although you can still get to Koh Lanta by ferry during the wet season, you'll find a limited number of bungalows and restaurants still open. Bad weather can shut down or make the ferry schedule unpredictable, forcing a stay in Krabi, the port town. Regardless, the small trickle of travelers who visit Koh Lanta during the off season are rewarded with long stretches of beach to themselves and the serenity of an island nearly void of tourists.
The Weather in Koh Lanta
The weather for the "shoulder" months between seasons on Koh Lanta can be summed up with one word: unpredictable.
Although the island practically shuts down around the end of April each year, you may enjoy weeks at a time in May with no rain. Even when the monsoon winds do bring rain, an hour or two of rain only makes the island humid—life goes on. That is, until the storms arrive.
Later into the rainy season (starting in June and July), big storms occur more and more frequently until they actually become damaging. Power outages are common, and activities such as scuba diving and boat trips frequently get rescheduled.
Koh Lanta Month by Month
The weather in Koh Lanta doesn't always follow a set pattern (Mother Nature does what she wants), but here is what each month is usually like:
- January: Ideal
- February: Ideal
- March: Hot
- April: Hotter
- May: Hot with mixed rainy and sunny days
- June: Rain
- July: Rain ; many businesses closed for season
- August: Rain; many businesses closed for season
- September: Heavy rain and storms; many businesses closed for season
- October: Heavy rain and storms
- November: Mixed sunny and rainy days; businesses begin to reopen
- December: Ideal
The High Season on Koh Lanta
The driest and busiest months on Koh Lanta are between November and April. December, January, and February are peak months for ideal weather. Average temperatures are pleasantly in the mid-80s in November and December but then climb progressively to a scorching 103 degrees Fahrenheit or more in late April. Luckily, a constant breeze will keep you cool as long as you remain close to the sea.
Even during the high season, Koh Lanta is not nearly as busy as the neighboring islands of Phuket or Koh Phi Phi which pretty well never shut down.
The Rainy (Green) Season on Koh Lanta
Rather than calling it the "rainy season" or "monsoon season," island residents simply refer to the rainy time of year as the "green season." The green season officially begins on May 1, although the monsoon is often a bit earlier or later to arrive.
May and June bring showers, however, the rain typically slacks off in July and August slightly, then returns with force in September and October before slowing down again in November for the new busy season to begin in Thailand. October is often the rainiest month on Koh Lanta.
The seasons are constantly in flux and depend on the arrival of the Southwest Monsoon winds that affect weather in all parts of Southeast Asia. Even if you visit Koh Lanta during the green season, you'll still enjoy consecutive days, perhaps longer, of sunshine with little to no rain.
What to Expect During the Off Season
The regular boat and speedboat service to Koh Lanta stop running around the end of April, however, you can still easily get to the island via minibus and ferry.
Although there will always be at least a few businesses still open, you will have a much more limited range of choices for eating and sleeping on Koh Lanta during the low season. Your resort may be the only option, and the menu may be limited. Beachside bars and restaurants mostly close up for the year. Even the bamboo beach furniture and thatched-roof huts get destroyed by strong winds and waves. New beach platforms and huts are constructed pretty well every season!
Although you will have beaches more or less to yourself, rubbish (both natural and man-made trash) accumulates on beaches more than usual. There is simply less incentive for businesses to keep the beaches clean for tourists.
The best thing about visiting Koh Lanta during the low season, aside from having beaches to yourself, is greatly reduced prices for accommodation and activities. You'll find the few accommodation choices still in operation willing to negotiate rates and throw in extras such as room upgrades. Tourist services such as motorbike rentals (very useful for getting around the island to find what is still open) are discounted by 50 percent. But use caution: The roads on the island often flood with standing water after downpours.
Depending on the timing, you could find yourself the only person staying in a bungalow or resort in beautiful places such as Long Beach. If life gets too lonely, rowdy Koh Phi Phi is a short boat hop away for enjoying some nightlife and meeting lots of backpackers.